#define Btn1_GPIO   35
#define LED1_GPIO   5
#define LED2_GPIO   4

bool led1On = false; 
bool led2On = false; 

void IRAM_ATTR Ext_INT1_ISR() {
  led1On = !led1On;
  led2On = !led2On;
}

void setup() {
  pinMode(LED1_GPIO, OUTPUT);
  pinMode(LED2_GPIO, OUTPUT);
  pinMode(Btn1_GPIO, INPUT_PULLUP);
  
    digitalWrite(LED1_GPIO, LOW);
  digitalWrite(LED2_GPIO, LOW);

  attachInterrupt(digitalPinToInterrupt(Btn1_GPIO), Ext_INT1_ISR, FALLING);
}

void loop() {
  if (led1On) {
    digitalWrite(LED1_GPIO, HIGH);
    digitalWrite(LED2_GPIO, LOW);
  } else {
    digitalWrite(LED1_GPIO, LOW);

    unsigned long currentMillis = millis();
    static unsigned long previousMillis = 0;
    const unsigned long interval = 100; 
    if (currentMillis - previousMillis >= interval) {

      previousMillis = currentMillis;

      
      if (digitalRead(LED2_GPIO) == LOW) {
        digitalWrite(LED2_GPIO, HIGH);
      } else {
        digitalWrite(LED2_GPIO, LOW);
      }
    }
  }
}